Many different types of prosthetic hip implants are known in the art. For example, prosthetic hip joint implants such as those found in U.S. Pat. No. 4,596,580 and U.S. Pat. No. 4,955,325 which employ acetabular cups are typical of prior art devices. However, these implant devices tend to be deficient where the primary acetabular cup has migrated superiorly to produce an oval acetabulum in the pelvic bone. In those circumstances, the surgeon typically must fill the superior portion of the acetabulum with bone grafts, ream a hemispherical cavity, and insert a new acetabular cup component. This is both time consuming, expensive and exposes the patient to risk. Further, when the acetabulum is oval in shape, it is difficult to achieve an intimate interface between the bone and the implant without use of allografts which are difficult to obtain and which present potential health risks due to spread of infectious diseases.
Oval shaped acetabular cups are known in the art. See EP 303,006. These cups, however, are provided only in a fixed configuration and cannot be altered to fit oddly shaped cavities that might be discovered during surgery.
A need therefore exists for an acetabular cup implant for use in hip restoration that provides an intimate interface between the bone and the implant and which can readily be adapted to fill oval acetabulums without the attendant disadvantages of the prior art devices.